Process and apparatus for making infusions



Sept. 18, 1945. M. H. GRAHAM PROCESS AND APPARATUS FOR MAKING INFUSIbNS Filed Feb. 7, 1941 Q SheetS-Sheet 1 mm R Wm A M 0 mm 9 Sheets--Sheet 2 M. H. GRAHAM PROCESS AND APPARATUS FOR MAKING INFUSIONS Filed Feb. 7, 1941 a 5 Z l/ H mr m 4 I. v A r r 6 F m 3. m 2 2' i 4 H A f --II\ M 4 u I n 3/ I J, 8 f H O 2 6 M H 7 B I U 4/ 3 j 1 M I z 2 I 1; I I M A I M 0 /1- b m 2 M .w 1 M a m w M 6 3 Z 0 3 lv 1 W F 6 Sept" 18, 1945.

p 1945. M. H. GRAHAM 385,132

PROCESS AND APPARATUS FOR MAKING INFUSIONS INVENTOR Sept. 18, 1945. M. H. GRAHAM PROCESS AND APPARATUS FOR MAKING INFUSIONS Filed Feb. 7, 1941 1 9 Sheets-Sheet 4 wmwmlmym INVENTOR Maia/m? c e H Grah am ATIONEY Sept. 18, 1945. M, H. GRAHAM 2,335,132

PROCESS AND APPARATUS FOR MAKING INFUSIONS I Filed Feb. 7, 1941 9 Sheets-Sheet 5 lNVENTOR Maw/dc e H Gr a/I am BY z, z

TI'ORNEY Sept. 18, 1945. M. H. GRAHAM 2,385,132

PROCESS AND APPARATUS FOR MAKING INFUSIONS Filed Feb. 7. 1941 9 Sheets-Sheet 6 INVENTCR Maurie e H @ra'ham Sept. E8, 1945. M. H. GRAHAM PROCESS AND APPARATUS FOR MAKING INFUSIONS Filed Feb. 7, 1941 7 Rd m mm m We Wm H M Sept. 18, 1945. M. H. GRAHAM 2,385,132

PROCESS AND APPARATUS FOR MAKING INFUSIONS Fi led Feb. 7, 1941 9 Sheets-Sheets lNVEN-TOR Maurice 1%. Graham ATTORNEY Sept. 18, 1945. 4 M. H. GRAHAM PROCESS AND APPARATUS FOR MAKING INFUSIONS Filed Feb. '7, 1941 9 Sheets-Sheet 9 INVENTOR Maurice H Graham ATTORNEY l meness. is, 1945 rnocsss Ann APPARATUS Fort ammo mrosrons Maurice H. Graham, St. Louis Park, Minn.

Application February a, 1941, Serial No. 877,895

(on. sa-n) 17 Claims.

The present invention relatesto the making of miles infusions and has for a broad object an increase in efliciency and economy inmaking the infusions.

Another broad object of the invention is to utilize superheated water for extracting coffee in a coilee maker without the application of other heat to the coffee maker itself so that-the infusion liquid will be kept at or near boiling during the extraction in spite of heat radiation losses common to all cofiee makers.

A iurthcr object of the invention is to provide. a batch process for making cofiee'iniusions in which superheated water furnishes the water supply for each batch and also furnishes the power means for recirculating the infusion liquid as the process continues.

it is a iurther object of the invention to pro vide an apparatus for efilciently carrying out the foregoing process of making coflee infusions without locally overheating them and thereby giving them undesirable flavors.

Another object is to provide anapparatus in which the infusion pot is readily separable from the remainder oi the infusion mechanism.

.It is a still further object to provide means for automatically terminating a coffee making operation in which superheated water is the medium used for the extraction. L

\ Additional objects such as the provision of detion and the appended drawings and claims.

Referring more particularly to the drawings Figure 1 constitutes a plan view of the entire device with the container for holding the coiiee grounds removed therefrom;

Figure 2 is an enlarged vertical section of the water heater indicated by the line 2-2 of Figure 1;

Figure 3 is a detailed view of the float valv mechanism shown in Figure 2;

Figure 3 is a detailed view oi the float valve mechanism shown in Figure 2;

Figure 4 is a detailed view of the superheated water supply valve shown in Figure 2; I

Figure 5 is an enlarged vertical section of the water heater indicated by line 6-4 of Figure 1;

Figure 6 is an enlarged vertical section of the infusion pot and coflee container taken on the line 6-8 of Figure 1; L V

Figure 7 is a vertical section of the coffee container and the holding mechanism for maintaining the infusion pot in operative position, taken on the line 1-1 of Figure 1 and with the codes container in position;

Figure 8 is a rear view of the connecting links 1 operated by the holding mechanism, as indicated by the line 8-8 of Figure 6;

Figure 9 is a modified detailed view 0! one of the arms oi the infusion pot holder shown in Figure '1 illustrating the position or the parts when the infusion pot is in position and the process is in operation;

Figure 10 is a view similar to Figure 9 showing the position of the parts when the infusion pot is held in an upper position prior to displacement of the holder arm; 0

Figure 11 is a view similar to Figure 9 in which v the infusion pot is removed and the holder arm is automatically latched in an open position:

Figure 12 is a vertical section in detail oi the condenser and recircuiator shown in full lines in Figure 6; I p

Figure 13 is a cross-sectional view oi the condenser taken on the line li -i8 of Figure 13;

Figure 14 is a bottom view of the apparatus showing the electric timer mechanism and the cut-out for the water heating circuits;

Figure 15 is a side view of the timing arm and associated mechanism as viewed in' the direction of the arrows lt-li in Figure 14, the parts being in the position assumed at the beginning of a coffee making operation: c

Figure 16 is an end view oi the timing apparatus taken in the direction of the arrows as shown in Figure 15: v

Figure 17 is an elevaticnal view of the mean for indicating the condition of the timing mechanism; I

Figure 18 is a view oi the timing mechanism similar to Figure 15 showing the position of the ing a particular application of the invention to a domestic coilee making apparatus;

Figure 25 is a bottom view of the heating element and thermostatic cut-out as viewed in the General description In general the invention consists of a process and apparatus which involves the utilization of superheated water as the source of heat in main ing cofiee infusions. Preferably the superheated water is also used as the sole source of power for circulating the infusion liquid through the coffee and the superheated water also preferably constitutes the sole source of heat.

The principal embodiment of the invention which is disclosed herein is particularly intended for use in restaurants and other places where a large amount of coffee must be furnished over an extended period of time and is hereinafter referred to as the "commercial type. A modified form of apparatus which is more especially designed to be used in the household is illustrated in Figures 21 to. 28, and is hereinafter referred to as the domestic type.

In both types of apparatus there is a compartment for receiving the infusion liquid which passes down through the coffee holder which is located near the top of the compartment and there is a second compartment constituting a source of superheated water. In both instances the second compartment is normally closed to the atmosphere so as to maintain a suitable steam pressure above the water which is heated therein.

The superheated water is introduced into the lower portion of the infusion-receiving compartment and heats the liquid therein and, in the embodiments disclosed in this application, the

superheated water passes into the infusion-receiving compartment through a tube which leads to a device adapted to efficiently transfer heat from the superheated water to the infusion liquid. This device is hereinafter referred to as a condenser" although in some instances very little, if any, steam enters the condenser and its primary function is to transfer heat to the surrounding body of infusion liquid. According to both embodiments the water which is still heated at least substantially, to its boiling point is conducted upwardly from the condenser to a point above the coffee in the coffee holder where it is discharged and is then permitted to flow downwardly through the coffee grounds into the infusion-receiving compartment.

Preferably the heated water discharges from the condenser through the jet of a jet pump.

the latter being located in the lower portion of the infusion-receiving compartment. The infusion liquid is drawn in through apertures in the jet pump and is forced upwardly through a tube discharging above the coffee holder. The superheated water thus constitutes the motivating fluid for circulating the infusion liquid through the coffee which is being infused. It is to be noted that the infusion-receiving compartment communicates with the rest of the apparatus through be satisfactory.

its open top and constitutes a portable container.

Referring now to the commercial type of coffee making apparatus, the water is superheated in a compartment generally designated 14 (Figure 1) and is conducted to the infusion-receiving compartment generally designated 21 through the pipe 94. A valve, generally designated at 92, is located in the pipe 94 between the water heating compartment H and the infusion-receiving compartment 2|. The valve 92 regulates the amount of water passing into the compartment 2| and, although it might be manually operated, it is preferably controlled automatically to open atthe beginning of the coffee making operation and to close at a predetermined time or upon the occurrence of some condition such as a change of temperature in the water heater or upon the filling of the infusion-receiving compartment. In the particular embodiment herein described, the valve 92 is closed at a predetermined time after the commencement of the coffee making operaremovable and tion. During this time a single batch of coffee grounds may be fully utilized in making a single batch of coffee and this is due largely to the fact that the water circulates atboiling temperature.

In the commercial type of apparatus the water heating compartment it is preferably connected with the city water supply line and a float operated valve mechanism insures that the supply of water in thecompartment will remain at a substantially constant level.

The temperature of'the water in compartment il is rather carefully controlled so as to maintain a fairly constant pressure in the vapor space above the water level and, since this pressure is a function of the temperaturef'of the water, the latter may be conveniently controlled by means responsive to changes in the vapor pressure.

In the commercial form of apparatus the water passing through the pipe 94 is conducted downwardly, as shown in Figure 6, through a tube ifiil and a condenser m2 located in the lower portion of the infusion-receiving compartment I78 and it then passes upwardly through a jet pump 883 and a tube E88 from whence it is discharged at a point above the cofiee in the coffee holder. After flowing downwardly through the coffee the liq= uid, which is now referred to as the infusion, collects in the compartment H8.

For best results the infusion process is usually conducted for a period of about four minutes, the rate of flow and the size of the infusion compartment being such that the infusion compartment becomes substantially full at the end of that period.

The pressure generated in the water heater is such as to insure that the water which is conducted into the fusion compartment will have sumcient latent heat to account for heat losses and maintain the infusion liquid substantially at the boiling temperature during the process. The pressure may be considerably higher provided that it does not exceed the minimum line pressure in the water supply pipe, but in practice a pressure of about eight pounds per square inch above atmospheric pressure has been found to As shown in. Figure 1, the commercial type of apparatus may be mounted on a base I'D constructed of sheet steel or other suitable material, and the'side portions of the base member may be bent over as shown in Figure 10 to enclose the control mechanism located underneath the base ill. At each of the four corners of the base in,

tubular legs I2 may be provided and these serve to reenforce the side portions and to provide additional support for the base member. The water heater generally indicated at I4 may be provided with a flange portion I6 and secured to the Water heater Referring now more particularly ,to the water heater I4 as shown in Figures 2, 3, 4 and 5. the heater is composed of cylindrical walls 26 which are flanged at the bottom, as previously indicated at I6. Abottom plate 28 is welded or otherwise secured to the inner portion of the cylindrical wall portion 28 to make a water-tight and pressure-resistant joint at 30. The upper portion or the cylindrical member 23 is formed into an annular flange 82 upon which is adapted to flt a cover member 34 and a rubber gasket 36 is placed between the cover and the flanged portion ofthe container to insure a tight connection when the cover 34 is secured'in place.

For the purpose of securing the cover member 34 tightly in place, the bottom plate 28 is provided at its center with a lug 38 which is welded or otherwise secured to the upper surface of the bottom plate. The lug 38 is threaded to receive a rod 4 which is threaded at each end and which extends through an aperture provided in the center of the cover 34. A hand wheel 42 which be made of a moldable heat-resistant material is provided with a threaded hub 44 which may be screwed onto the upper end of the rod 40. Preferably the cover 34 is slightly countersunk at its center to receive a brass bushing 46 which prevents leakage about the rod 40 when the cover is fastened in place.

At the rear of the water heater a float valve 48 is disposed so as to communicate with an outside source of water under pressure such as from a city water main. The float 50 normally maintains a constant level of water in the water heater I4. A threaded portion 52 of the water heater I4 receives the packing nut 54 which in turn forms a union between the flanged pipe 56 and the threaded portion 52. The pipe 56 leads to the outside source of water mentioned above and bears a shut-ofi valve 58 for completely shutting ofl the water supply if it be desired to clean out the water heater for example. The threaded portion 52 is also tapped to communicate with the pipe 56 and to receive the threaded end 60 of the float valve. As shown in Figure 3, the threaded end 60 has a small passageway 62 centrally drilled to allow water to flow into the passageway 64 and thence through the stub pipe 36 and into the water heater proper. A valve needle 68 has a reduced portion I0 which is beveled at its end I2 to flt against the passageway 62 and thereby shut oiT the flow of water from the outside source. When the needle 68 is retracted, water will again flow into the water heater. At the end of the valve 48 opposite the connection with pipe 2t is another reduced threaded portion 14 through which the valve needle 68 can slide.

A U-shaped bracket member I! has an extension I8 which is drilled to flt about the threaded portion 14 and a nut 80 is drawn up tightly to secure the extension 18 against the shoulder 01' the threaded portion I4. A packing nut 82 prevents water from leaking past the needle 80. A rod 84 is secured to the float 50 and is bent at 80 so as to circumvent the rod 40 in the center of the water heat. The end 08 of the rod 84 opposite the float 50 is bent upwardly at right angles and is pivotally secured at 80 between the ears of the bracket 18. The right angle portion 88 of the rod 84 is so disposed as to bear upon the needle 68 when the float is in a horizontal position and thus shut off the water supply. It the level of the water within the water heater is lowered the float and its rod 84 will relieve the pressure on the needle 68 and thus allow water to flow in and re-establish the normal level.

At the opposite side of the water heater I4 is another valve 82 which is placed in the outlet pipe 84 leading from the water heater. The end of the pipe 94 is threaded and is screwed into the top 86 of the wall 28 oi the water-heater. This hot water outlet may be quite close to the normal water level as shown in Figure 2 because the rate of outlet flow never exceeds that of the inlet flow and as a result the water level never varies much from the normal.

The valve 82 is preferably a needle valve of the S-type as shown in detail in Figure 4 and has a small tapered opening into which flts a correspondingly tapered needle point 88. The

needle point 98 is at the end of a U-shaped valve rod I00, the other end of which extends down through the base I0 and will be later described in detail. The needle slides in the threaded portion I02 of the valve 82 which in turn bears the packing nut I04 to insure against leakage of the superheated water.

The mechanism preferably employed for controlling the temperature and pressure developed in the water heater will now be described. At the bottom of the water heater is a pipe I 06 which extends through the bottom plate 28 of the heater and through the base I0. The pipe I08 is welded or otherwise secured to the bottom plate 28 so as to form a pressure-tight joint. The pipe I08 preferably extends for a short distance above the bottom plate so that settlings will not clog the small openings I08 which connect the pipe I08 with the interior of the water heater I4. For additional insurance against clogging a small screen 0 may be placed over the pipe I08 and its openings I08. The pipe I00 is .bent at right angles beneath the base I0 and communicates with a metal bellows II 2, which expand and contract in accordance with the pressure developed within the water heater I4. At the other end of the bellows is fixed a thrust rod II4 which bears against a member II6 pivoted to the base I0 by the post II8 as shown in Figures 5 and 14. Another thrust rod I20, shown in Figures 2 and 14, bears on the opposite side of the member H6 and is biased thereagainst by spring I 22. The thrust rod I20 slideswithin a guide I24 which is threaded to flt into an- L-shaped bracket I28 which is secured to the under side of the base I0. The threaded guide member I24 is adjustable in the bracket so as to vary the tension of the spring l-22.

The pivoted member II6 engages two adjustable screws I28 and I30 which are insulatedly mounted on two spring conductors I32 and I34, each of which is in circuit with a heating element as shown by the wiring diagram in Figure 20. The spring conductors I38 and I88 are mounted on a bracket I35 which in turn is bolted to the under side of the base I0. Each of the spring conductors I32 and I34 has a silver contact member I38 disposed opposite Silver contact members I40 mounted on a bracket I42 which is mounted on the under side of the base member I and the contacts l40 are connected to the source of current when a main switch is closed, as, shown in Figure 20. The adjustable screws I28 and I 30 may be set in such a manner that either contact is made shortly before the other. When the contact I38 of the spring conductor I32 is closed the U-shaped heater member I44 is energized and when contact I38 of the spring conductor -i 38 is closed the U-shaped heater member I48 is energized. Since the circuits including the two heaters I 44 and I48 are parallel circuits it follows that either or both may be energized and deenergized, depending on the setting of the adjustable screws I 28 and I80. .As will be observed, the contacts are closed by the spring I22 until suflicient pressure is generated in the water-heater. The adjustment of screws I28 and I30 predetermines the pressure at which the heater elements will be deenergized, and since pressure is a function of temperature, will also control the temperature which the superheated water attains in the water heater I4. As a practical matter the wear on the silver contact points will be equalized because only one heater will be energized and deenergized during standby periods for keeping the water hot, and the second heater will be energized and deenergized while the coffee maker is in use, the first heater remaining energized in that case.

Each of the heater elements I44 and I48 is preferably composed of a metallic resistor I48 which is sheathed in a copper tube I50 and insulated therefrom by a highly refractory filler I52. The tubes are each secured to a base member I54 to form a water-tight joint therewith and the base members I54 are welded or otherwise securely fastened to the bottom plate 28 of the water heater. The resistor ends, surrounded by insulating material, extend through the base members. I54 and the bottom plate 28 of the water heater and are threaded at I 56 to receive nuts I58. Washers I60 of electrical insulating material fit about the threaded ends and are interposed between the conducting wires I 62 and the bottom plate 28.

A steam pressure gauge I64 is attached to the upper portion of the water heater so that its tube I66 communicates with the space above the normal water level in the water heater.

In the cover of the water heater is placed an adjustable bleed valve I68 for allowing a slow continuous escape of vapor from the space above the normal water level. Thereason for employing a bleed valve is to rid the water heater of air which may be dissolved in the cold entering water. Since the cofiee maker utilizes the superheated water rather than the vapor formed, the air driven out of the water by heating will accumulate in the space above the water level and commingle with steam. In the absence of a vapor outlet the proportion of air to steam becomes greater and greater. With this steam-air vapor phase over water a greater pressure is attained at the same temperature of the water than where a pure steam phase exists over the water at the same temperature. If the temperature of the water is controlled by a pressureresponsive means, the predetermined pressure is reached where the water has not yet reached its proper temperature unless the air is removed. The bleed valve I68 remedies this situation by preventing the accumulation of air in the space above the water level and thus rendering the pressure control an accurate measure of the temperature as well. The bleed valve I68 consists of a threaded tubular member with an outside opening I10 communicating with the vapor space of the water heater. The needle II'iseats in a reduced portion of the opening as is common practice in needle valves. To efiectively bleed the air from the .water heater, it is but necessary to adjust the needle so that .a barely perceptible amount of vapor escapes.

A safety valve I14 is also placed in the cover 88 01 the water heater I 4 to insure against an accidental build-up of pressure. The valve I141 is capped by a rubber member I18 which is flanged to fit in an annular groove about the valve. The resilience of the rubber member I18 is such that at a predetermined pressure the member will be blown off the valve, allowing vapor to escape. At operating pressures the rubber member is selfsealing in the annular groove of the valve. Such valve may also be used as a manual vapor vent since when it is depressed theseal is broken and vapor may escape about the sides of the valve. Although this type of safety valve is preferred because of its simplicity, any other safety valve may be employed.

Infusion mechanism Referring now to Figures 1 and 6, the pipe 84 conducts superheated water from the water heater to the infusion mechanism, including the infusion-receiving compartment or pot I18. As will be explained, the infusion pot I18 is completely separable from the rest of the apparatus, and it is to be noted that the infusion pot is simple and inexpensive in construction. A dish-shaped device I18 may be secured to the base III to collect any coffee which may drip from the mechanism. At a position above the infusion pot I18 the pipe 94 is bent downwardly in a vertical leg I which at its lower end communicates with a heat-exchanging device or condenser I82 near the bottom of the infusion pot I 18.

As shown in Figures 12 and 13, the condenser I 82 preferably comprises a cylinder having a diameter which is relatively large in proportion to its height and it is provided with interior ballles I84 for imparting a zigzag motion to the superheated water.

The zigzag action of the superheated water facilitates the transfer of its superheat to the infusion liquid thus preventing or minimizing the flashing of the superheated water into steam upon reaching atmospheric pressure.

After circulating through the condenser I 82 the water passes out through an opening which is preferably fitted with a threaded reenforcing collar I 86, as shown in Figure 12. A small nozzle I81 is screwed therein and forms the jet of a jet pump as will be described hereinafter. The size of the nozzle I81 is preferably such that the water is maintained under superatmospheric pressure until it issues from the nozzle. In most instances the water will have given up its superheat in the condenser I82 and will issue from the nozzle at a temperature which is not quite suilicient to cause boiling. Whether or not there is a small residue of superheat remaining in the water after it has passed through the condenser is immaterial since most or the steam formed will condense when it strikes the infusion liquid and tend to maintain the infusion liquid at boiling. 1 The ideal condition is attained when the amount of incoming superheat exactly balances the heat losses in the apparatus. the net effect being to maintain the infusion liquid exactly at its boiling temperature without actually boiling the infusion liquid. The maximum of extraction is thus assured without causing the infusion liquid to acquire the usual bitter taste which results from boiling.

The expression superheated water where it appears in the present specification and claims designates water in the liquid state at a temperature above boiling, and under superatmcspheric pressure sumcient to Prevent substantial conversion of the water to steam and adapted to cause the water to be delivered as a positive liquid stream to the coilee for infusion. As previously pointed out the degree of superheating will be such that the water will be delivered to the coffee for infusion at or about boiling temperature (but preferably without actual boiling) instead of at a temperature substantially below boiling, for example 150 160, as is frequently the case with various prior forms of coffee infusing'apparatus. The drop in temperature of the water from itsinitial superheated condition in the water heater to its point of delivery to the coil'ee will determine the degree of superheatins which is required in order that the water may be delivered in the condition indicated. The superheat of'the water may not only compensate for heat losses in the water during transit prior to infusion but supply 7 heat to the water which has already been con-' verted to infusion liquid to maintain the liquid during the entire infusion process at a temperature suitable for recirculation through the coffee and dispense with the necessity for this purpose or heating mechanism in,c0njunction with the infusion-receiving chamber. Under these circumstances the temperature difference between the superheated water in the heating chamber and the infusion liquid in the infusion-receiving chamber may be 36, more or less, due to heat losses, so that if the infusion liquid is to be maintained near boiling temperature, 204 for example, it will be apparent that the water must be initially superheated in the heating chamber .to a temperature substantially above boiling- Unless the incoming water at its superboiling temperature before delivery is under appropriate superatmospheric pressure it is likely to be converted to steam. This would be extremely undesirable, since the superheated water supplied from the heating chamber constitutes the entire supply for making the infusion, and would not if in the state of steam be in condition for delivery to the coffee for infusion unless water for infusion is supplied from an independent source which'last is not true with the present invention.

For the reasons indicated it will be understood that steam and mere hot or boiling water are not th equivalent of superheated water in carrying out the objects of the invention.

The recirculating tube I88 leading upwardly from the condenser has an enlarged lower end I88 which is threaded to flt the outside diameter of the reenforcing collar I88. The enlarged end I89 also is provided with several apertures I88 drilled therein for allowing infusion liquid to en-,

to! at a point below the outlet of the nozzle I81. The device thus constitutes a Jet pump and the force or the hot water issuing from the nozzle I81 is sufllcient to carry along with it a portion of 9,888,189 r I r the infusion liquid for recirculation. An annu- I lar fill I8I may be provided in the tube I88 lust above the nozzle I81 to create a Venturi effect. The tube I88 extends vertically upward. from s the condenser and passes through the supporting tube I88 in rigid relationship with the supporting post 22.

The lower nut I88 also retains a circular shield I88 in position as shown in Figures 6 and 7. The shield I88 cbmprises a circular disk which is bent lo backicnitself at 288 for a distance and then is forfned into a vertically depending cylindrical portion 282 which, acts as a guide for the mouth of the infusion pot I18 when it is raised into position. Buttons 284 may be placed about the 20 cylindrical portion 282 to prevent contact betweenthe metallic cylinder and theglass infusion pot I18, and to maintain more rigidly the infusion pot in position during an infusion process.

As shown in Figure '7, two openings are provided as in the top of the shield I88 and are fitted with flared guide members 288. The openings are for allowing infusion liquid to drain back into the infusion pot after having percolated through the coffee grounds.

- suflicientdistance to act'as a supporting post for the coffee container indicated generally at 288.

The outer walls of the coffee container are circular and form a cup-shaped receptacle 2I8.

In the center of the receptacle is secured an up- The tube I88 extends above the arm I82 for 9.

about the extended and of tube I88 to support the coflee container. Two depending tubes 2J4 diametrically opposed lead'from the bottom of infusion liquid from the container. These tubes 2I4 are disposed so as to enter the flaring guide members 288.

A coffee basket for retainingcoifee grounds during the infusion process consists of cylindrical walls 2 I 8. a central sleeve portion 2I8, and a metal soldered to the central sleeve portion 2I8 at a short distance from the lower end of the sleeve so that ,a clearance space exists between the screen 228 and the bottom of the receptacle 2I8. The coffee container288 is equipped with a circular cover 222 which as a central aperture spreadermember 224. Openings 228 are drilled in the spreader member 224 communicating with a passageway leading from the recirculating tube I88. A flared guide collar 228 is screwed into the spreader member 224 so as to make an effective Joint between the tube I88 and the spreader member 224 when the cover 222 is placed in position. A knob 288 made of non-conducting material is screwed upon the threaded portion of the spreader member 224 so as to secure rigidly (both the 7 knob and the spreader member to the cover 222. A distributor plate 282 is held rigidly to the spreader member by the guide collar 228 which has a reduced shoulder portion 284 fitting into a central hole drilled in the distributor plate. The

. the receptacle 2I8 for the purpose of conducting.

' screen bottom 228. The cylindrical portion 2I8 50 fits closely within the wall of "the receptacle m 00 to receive a threaded reduced portion of the distributor late 232 has an upturned rim 236 which fits snugly against the inner periphery of the receptacle 2I6 and has numerous small holes 246 disposed in such a manner that the recirculated infusion liquid will drip evenly over the coffee grounds placed on the screen 226 to secure maximum extraction. A handle 238 of non-conducting material may be secured to the coffee container 268 in the usual manner.

Supporting mechanism for infusion pot Referring now to Figures 1 and '7, the mechanism for holding the infusion pot I18 in operative position is shown. Arms 262 are rigidly secured to pivot rods 264 which are journaled at opposite ends in the brackets 246 and bracket 246 as shown in Figures 1 and 8. Knobs 256 are secured to the respective arms 242 for manually lifting arms 242 or lowering them. Extending downwardly from the arms 242 are inwardly turned L-shaped members 252 with lugs 254 at their ends as shown in Figure '7. The neck of the infusion pot I18 is fitted with a metal band 256 which is bent at its upper edge into a U-shaped flange 258 as shown in Figures 6 and '1. The ends of the band are bent outwardly into brackets 266 which are bolted to a handle 262 for the infusion pot, as shown in part in Figure 6.

When the pot I18 is in position the lugs 254 of the L-shaped members 252' are caught in the U-shaped portion 258 of the band 256 so that the entire infusion pot 118 is supported by the arms 242 as shown by the full line view in Figure 7. It may be seen that whenever it is desired to remove the infusion pot I18 from the support or to replace the pot on the support it is necessary to raise the infusion pot manually to the upper dotted line position shown in Figure 7 before the arms 242 can be moved to or from their dotted line position. It is thus impossible for the arms 242 to be raised while the infusion pot is in position so as to allow the infusion pot to drop from its support by accident.

The arms 242 and associated mechanism are counterparts and in addition, operate simultaneously so that if one of the knobs 256 is lowered or raised, the other will move accordingly. In addition to securing and supporting the infusion pot, the arms 242 also initiate an infusion process when they are lowered to the full line position shown in Figure '1, as will be described below.

Means for controlling operation of. infusion mechlam'sm Referring to Figures 1 and 8, the pivot rods 244 have another set of arms 264 integrally or rod 216, the latter being shown in Figures 6, 8, )18

and 19. A tension spring 212 connecting the bent arms 2,66 biases them together. The bracket 248 which supports the pivot rods 244 is secured to the post 22 by a bolt 214, and a rectangular ofi'set on the bracket 248 fits into a similar countersunk portion in the post 22 in order that the bracket 248 will not turn about the bolt 214.

When the pivot rods 246 are turned by raising knobs 256, the pivoted ends 265 of the arms 264 are lowered, thus lowering and slightly separating the bent arms 266. In consequence of this movement, the thrust rod 216 is also given a downward movement.

As shown in Figures 18 and 19, the lower end of the rod 216 slides vertically in a guide member 216 attached to the supporting post 22. Attached to the rod 216 at a point above the bearing member is a bracket 211 which is adapted to hold a latch arm 218 for pivotal movement as at 216. A roller 286 is secured to the upper end of the arm 218 and a small leaf spring 282 biases the upper end of the arm 218 outwardly so that the roller 266 normally engages the lower horizontal surface of a lug 283 which is fixed to the valve rod I66, as shown in Figure 18.

When the handles 256 are lowered, the upward movement of rod 216 and roller 266 raises the rod i66. Before the upward movement has ended, however, the roller will move out from under the lug 283 permitting the valve rod I66 to fall or to be held in upper position by detent 286. The withdrawal of the roller 286 results from the engagement of the bent end 286 of the arm 218 against the edge of the guide member 216.

Near the end of the valve rod I66 is a notch 285 for engaging the detent latch 286, as shown in Figure 15. Immediately above this notch is a recessed portion 281 into which the detent member 286 can extend when the thrust rod 216 is at the lower of its two positions, as shown in Figure 19. A collar 288 is fixed to the thrust rod 216 and a compression spring 289 is posi= tioned between the collar and the under side of the base I6, thus tending to lower the rod 166 and to urge the needle valve 92 to closed position. When the handles 256 are lowered, valve rod 166 is raised and needle valve 92 is opened and superheated water is allowed to flow into the infusion device until the detent 286 is withdrawn from the notch 285.

The detent 286 for latching-the rod I66 in its 40 upper position has downwardly bent ears 296,

as shown in Figures 15 and 16, which are mounted on the reduced portion 292 of the post 286. The post 294 is rigidly bolted to the panel 286 which in turn is bolted by means of posts 288 to the partition 366. Another partition 362 (Figure 5) is symmetrically positioned with respect to the partition 366 and they extend for the width of the under side of the base I6 so as to furnish reenforcement for the base.

The detent 286 has a lateral extension on the opposite side of'its pivot terminating in a downwardly extending dog 364 as shown in Figures 15,

18 and 19. A wheel 366 with a cam portion 666 engages the dog 364 so as to move the detent 286 to and from an engaging position with respect to the notches 285 and 261. Thus when the dog 364 of the detent 266 rides upon the cam portion 368 of the wheel 366 the detent 266 will be withdrawn and, the valve rod I66 will move to its lower position. When, however, the lug 866 rides on the circular portion of the wheel 666, the detent 286 is in its latch position and if the rod I66 is now raised the detent 286 will enter the notch 285 and the rod I66 will be held in its uppermost position.

The lower end of rod I66 engages a leaf spring 3I6 which is secured to a bracket 3I2 attached to the panel'286 as shown in Figures 15 and 16. Also secured to the bracket 8I2 are two spring contact members 3I4 and M6 which are normally biased apart as in Figure 19. The contact members 3I4 and 3I6 are electrically insulated from each other and from the leaf spring 8I6 by means of non-conducting washers 3I8 which also space the spring members at their -respect to the panel 280.

ward bias of the leaf spring 2I0 will close the contacts 3 and [I8 as shown in Figure15. But when the rod I is in its lower position as shown in Figure 19, the end of the rod pushes the leaf spring M0 to a lower position in which the memassures heater I4. When water has reached the level shown in Figure 2, the float 50 will beraised her 822 does not engage the lower spring contact 2. The lower spring contact IIO also bears a; non-conducting button 324. The button 224 is adapted to engage the top ofthe dog 204 so that when the cam portion 300 of the wheel 300 holds the dog 3% in a raised position, the contacts 2I4 and II! will be held closed without resorting to the member $22 of the leaf spring 3I0. This condition obtains when the partsare in the position shown in Figure 18s The cam wheel tilt is rotated in a counterclocka wise direction by a self-starting electric timing motor are mounted on the partition tilt as shown in Figures 14 and 16. The drive shaft of the timing motor 320 extends through the partition and terminates in a gear wheel 028 which is in mesh with the longer gearwheel230. The gear 820 is 7 vents the gear 330 from moving laterally on the i shaft 332. Integral with the cam wheel B is a hub 0H which terminates in a bearing surface 342 for engaging the panel 298. The cam wheel 300 and its hub at I are keyed to the shaft as: at 344. A washer 348 on the opposite side of the panel is held against the panel by'the key 348 so that the shaft 332 cannot move laterally with The control knob as (Fig end of the shaft 382 has a pointer 340 integral therewith for indicatingthe fraction of the full infusion time which has elapsed at any instant. When the pointer indicates zero the cam wheel is in the position shown in Figures 15 and 19. If it be desired to interrupt the infusion process or to begin a new one before the previous one has run its course, the control knob 334 may be used 1 to advantage, as will be more fully discussed under the operation of the device.

A flasher eye 850 shown in Figure 1 is illumihated by an electric bulb 352 as indicated in Fig- Operation In the operation of the device, the supply pipe 50 is connected toan outside source of water under pressure, such as city water, and the valve 55 is opened to allow water to enter the water um 17) fixed to in low this normal level, pressure on the needle (I is relaxed and water forces its way into the heater I4 through the stub pipe 40.

To heat the water the main switch 254 is closed. When the heater is cold, both the contacts I32 and I14 are closed because the bellows II2 of Figure 2 is in a contracted position. Now. however, as the water heats and steam pressure is developed, a predetermined pressure will break one of the two contacts I02 or I24. Another predetermined pressure slightly greater than the first will break the second contact and if no superheated water is withdrawn from the heater the second contact alone will open and close in response to the pressure charges in the heateras the heater idles, it being necessary only to maintain the proper heat and pressure in this case without heating fresh water. When superheat- I ed water is being withdrawn for the infusion process, the second contact remains closed and the opening and-closing action occurs at the first contact. In practice the contacts thus wear evenly and it is not necessary to adjust the contacts as frequently as if .onepontact were subject to greater wear.

A satisfactory working pressure for the water heater has been found to be eight pounds per squareinch and, if thls pressure is chosen: the first contact may be set to open slightly below eight pounds pressure and the second contact may be set to open slightly above eight pounds pressure. At eight pounds per square inch pres-.

sure, the superheated water will-maintain a temperature of about 235e Fahrenheit. This temperature will vary, of course, within limits of a few degrees due to atmospheric changes in pressure, but .the temperature of the superheated water is not critical. The object of using superheated water is to supply water which wm remain at or near the boiling point during the infusion process in spite of the inevitable radiation and conduction of heat'from the infusion device.

When it is desired to make coffee infusions, coffee grounds in the proper proportions for-one batch are placed in the coilee container 2I0 and the cover 222 is fitted'in place. The empty infusion pot I18 is lifted manually into the position shown in Figure 6 and while being held in an upper position as indicated by the dotted line view in Figure .7, the handles 250 are snapped down into the full line position. The infusion pot locks itself on the supports 252 as previously described.

At the instant the handles 250 are lowered to their holding position the rods 244 turn and so also do the connecting levers'284 which are secured respectively to the rods 244. The rod 210 is raised by the rotary motion of the levers 204 through the links 288 and carries with it the valve rod I00 against the pressure of spring 209. The

relationship of the rods 210 and I00 is shown in Figures 18 and 19. As the rod'210 reaches its upper position the roller detent 280 snaps from under the lug 203 because the arm 218 is biased in a counterclockwise direction by the cam action of the end 284 of the arm218 on the side of the The rod I00 thus released has a tendency to return to its lower position but cannot since the detent 286 now engages the notch 285 at the lower end of the rod I00.

Since the valve'rod I00 is now in upper position the needle valve 92 of Figures 2 and a will be open a d will allow superheated water to flow from the water heater i4 through'the pipe 64 and the vertical tubular position I36 to the condenser I82 as shown in Figure 6. The water will make its way through the tortuous path formed by the vanes I34 within the condenser and will escape through the nozzle 861, at first merely flowing back through the openings i66 into the infusion pot H6 but later. when the liquid level covers the openings, the water issuing fromthe nozzle will impel the liquid of the infusion pot up the recirculating tube E66. When the liquid strikes the member 224 it is caused to divide and to spray out from the openings 226 over the spreader plate 232. Openings 246 in the spreader plate are so arranged and spaced as to allow the recirculated liquid plus the incoming water to drop evenly overthe screen 226 on which coffee grounds are placed. After passing through the screen 226 the infusion liquid collects in the bottom of the container 2i6 and flows out of the two short tubes 2 back into the fusion pot (Figure 7). It will be noted that it is not necessary to add outside heat to the infusion pot during the infusion process. The infusion liquid remains at or near boiling by virtue of the latent heat in the superheated water which takes care of external heat losses.

When the infusion process is completed and the valve 621s shut oil, the infusion pot may be removed by manually lifting the pot with one hand and raising a handle 266 with the other. -The infusion potgis then lowered and the infusion liquid poured therefrom. It will be noted that it is impossible-to raise the handles 256 without first raising the infusion pot I16. Thus it is impossible for an operator to cause the infusion pot to drop from its support by accident or inadvertence without first having a firm grasp of the handle 262 of the infusion pot H8.

The operation of the timing mechanism will now be described. At the beginning of the operation and with the infusion pot in place, the device is in the condition shown in Figure 15. The detent 266 holds the valve rod I66 in an upper position so that the valve 92 is open. The

spring 3"! which bears against the bottom of the rod I66 is also in an upper position. The hook member 322 on the leaf spring 3i6 holds the contact 3i6 against the contact 3 so that the circuit to the electric clock is closed as shown schematically in the diagram of Figure 26. Parallel to the clock circuit and also operated by the contacts 3M and M6 is the signal lamp 352, and

whenever the clock motor 326 is energized the signal lamp 362 will so indicate. The electric clock and the cam wheel 366 continue to turn until the cam reaches the initial starting position of Figure 19. However, when the dog 364 rides up to the high portion 368 of the cam 366 the detent 266 releases the valve rod I66 so that it assumes its lower position as in Figure 18, to close the-needle valve 92. Now the hook member 322 of the leaf spring 3i6 no longer holds the contact 3| 6 against the contact 3i4. If there were no ether provision for keeping the 366 may thus be constructed to cause the motor w and signal light to remain energized for the proper lengthof time for such drainage. When the light goes oil the operator may remove the infusion pot. With an infusion pot of six-cup capacity, it has been found advisable to have a rate of flow of superheated water such that the process will be complete in four minutes with an additional fifteen seconds drainage period.

The knob 334 is mounted on the shaft 832 at the side of the apparatus as shown in Figures 1 and 17. The knob turns with the cam wheel and is both an indicator for the instantaneous fraction of time which has elapsed in any one run and is a manual adjustment means for shortening the length of time for a run or for bringing the timing mechanism back to initial starting position without having to wait for the timing clock to rotate the cam wheel 366.

Independent switches 356 control the energization of two standby heaters 24 as shown in Figures 1 and 20. An infusion pot and its contents may be placed on a'standby heater to keep the infusion liquid hot for immediate use.

Referring now to Figures 9, 10 and 11, an additional safety device may be employed to prevent the starting of a run when-the infusion pot is not placed in position. A detent W6 is pivoted to a bracket 362 which in turn is fastened to the underside of the member I68. A light spring 364 biases the detent 366 in a counterclockwise direction.- When the infusion pot is not in position the detent will maintain the supporting arms 252 in theirupper position so that they cannot be lowered to start the apparatus'in operation. When the infusion pot is held in its upper position the detent 366 is raised by the edge of the infusion pot and the supporting arms 262 may then be lowered as in Figure 10. The infusion pot is thereafterallowed to drop down into its lower self-latching position as shown in Figure 9.

Modified apparatus especially intended for domestic use The invention may be'incorporated in a domestic model as well as in a commercial model. The modification shown in Figures 21 and 27 illustrates One application of the invention to domestic use.

The infusion 366 of Figure 21 and may be constructed of metal, heat-resistant glass, or other suitable material. A handle 368 is attached to a band 316 which encircles the infusion pot near its upper edge and the infusion pot forms a support upon which the remainder of the apparatus rests, and from which contacts 3M and 3"! closed the motor 326 would be deenergized before the cam 366 reached its original starting position. In order to keep the motor and signal light energized an insulated button 324 is secured to the lower contact member M6 and engages the top of dog 364 to maintain the contacts closed whenever the cam holds the dog in an upper position. The timing motor it is readily separable. The superheated water chamber 312 has a handle 314 attached thereto for convenience in removing the infusion apparatus from the infusion pot.

A tube 316 is centrally disposed with respect to the infusion pot and the superheated water cham= ber for conducting superheated water from the chamber 312 to the condenser 376. Surroundin pot in this case is indicated at tom of the chamber 812 and has a flanged portion 882 which is soldered or otherwise secured to the bottom of chamber 812 to form a water-tight joint. The tube 880 preferably terminates short threaded at its lower end.

Near the bottom of the chamber 812. tube 388 is equipped with openings 884 for the introduc tion of superheated water from the chamebr 812. At the upper end of the tube 880 the tube is closed except for a small Vent 885 to prevent water from being forced into the infusion pot 868 before it becomes hot. A reduced threaded portion 3% extends upwardly from the tube 388 and a flared to form a short skirt which overlies the rubber gasket and the rim or the chamber 812. "In the cover 892 of the superheated water chamber is a spring safety valve 408 of usual construction which may be set to release at about eight pounds per square inch pressure.

The tube 815 extends to within a short distance of the top of tube 888 so as to maintain a communication.therebetween. At its lower end the tube 888 is constricted below the openings ly below the bottom of the chamber 312 and is I electrically insulatedfrom the bracket by insulat- 884 and the tube 818 is secured therein in a watertight manner. A nut 488 is threaded on the lower end of tube 380 and rigidly secures togather the chamber 212. the heating element casing 412,. and the heating element assembly with its cover plate 4i 2 ihe lower end of the tube 818 extends into the' condenser 818 and is removably wedged into the circular plate M4 as shown in Figures 23 and 24. The plate 4 is disposed laterally in the condenser so that the superheated water entering the condenser 818 through the tube 318 enters below the plate. The water is forced outwardly to the openings 416 and thenceback to the upper central part of the condenser 818. 1A threaded nozzle 418 is concentrically disposed with respect to the tube 818 and the condenser 818 in such a manner as to form a narrow annular opening 428 for directing the incoming water upwardly in recirculating tube 42 2.

The recirculating-tube 422 is threaded to an "enlarged lower end 424 which is screwed upon part of the threaded portion of the nozzle 418. Also in this enlarged lower end 424 are inlet openings 428 which allow infusion liquid to enter be-' low the mouth 42!! of the nozzle 8 and to be tail in Figure 27. A detent M8 I 488 which is cup-shaped and equipped with a central sleeve 488 which fits about the recirculating tube 422. The bottom v440 of the basket 428' is perforated to allow the infusion liquid to drain therefrom, or the bottom may consist of a screen or other perforated means for accomplishing the same purpose. a

A cover 442 fits over the top of the coflee basket 438 and is also perforated in order to distribute the liquid evenly over the coffee grounds. A short tubular member 444 at the center of the cover 442 fits about the sleeve 428. At the under side of the coffee basket 438 is a collar 448 as shown in depivoted at 458 to the collar 448 is biased by spring 482 so that the end 454 of the detent extends through a slot 458.

"tube 880 as shown in Figure 22.

Mounted on the underside of plate 2 is a bracket 484 which bears the terminals 488 and 488, as shown in Figure 25. The terminals are ing washers 418 and may be connected with any suitable source of electricity. A conducting piece 488 is fastened at one end to a freeendl" of the heating element 488 as shown in Figures 25 and 28; A screw 418 bearing an insulating washer 488 is fastened to the rectangular piece 482 and passes through a fiber insulating member 484. The fiber insulating member 484 and the rectangular piece 482 are further fastened to the base 4| 2 by means of screw 486. The free end 418 of the heating element extends through the fiber piece 482 which I positions it at the center of an opening 488 in rectangular piece 482 and the base 4 l2. The other impelled upwardly through the restricted passageway 421 by the force of the water issuing from the nozzle 4 i 8.

At the upper end of the recirculating tube 422 is anotherenlarged portion 428 about which a hood-shaped spreader member 488 extends. The upper end 428 of the recirculating tube 422 is internally threaded and screws upon the lower threaded end of the tube 888. A guard plate 482 is held in position between the upper endof the recirculating tube 422 and the nut 488. Openings 484 in the enlarged upper end 428 of the tube 422 free end 411 of the heating element 488 is connected with a conducting piece 412 which is fastened to terminal 488 by nut 414.

The conducting piece 488 is insulatedly. mounted on the base 2 at482 and terminates in a contact point 484. Another bracket 488 is mounted onthe base 2 by screws 488 and carries a binding post 488 connected by wire 888 to terminal 488. Also attached to the binding post 489 and in electrical contact with the wire conductor 888 is a spring contact 802. The spring contact terminates in. a contact point 584 which is adapted to engage contact 484. An adjusting screw 808 is mounted insulatedly on the spring 7 contact 882 so that it is engageable by the free end of a bimetallic strip 508 as shown in Figures will bend inwardly, engage the end of the adjusting screw 508 and thereby break the contact 484, 504 to deehergize the heating element 460.

In the operation of the modification shown in Figures 21 to 28, the coileeicontainer 436 is lowered on the tube 422 by releasing the latch 448. If desired, the condenser 81B and the lower end 424 may be unscrewed from the tube 422 thus allowing the cofiee container 436 to be completely removed from the tube 521i. The distributing cover M2 is then removed and the desired amount of coffee grounds is placed within the coffee container. "The cover is replaced and the coffee container moved up the tube 422 to its latched position as in Figure 21. The entire infusion unit is then placed in position on an empty infusion not 868 and in this position, the condenser portion 318 will be a short distance above the bottom of the infusion pot. The cover 390 of the superheated water chamber 312 is unscrewed from the threaded top of the tube 880 and the desired amount of water placed in the chamber. The

terminals of the infusion device are connected to v a suitable source of electricity and since the con-= tacts 494, 504 are now closed, the heating element 460 will begin to heat the water in the chamber. Due to expansion of the water and the presence of vapor over the water, a pressure immediately begins to build up within the chamber.

The tendency during this warming up process is to force water through openings 384, up tube 880 and into tube 316 and infusion pot 388. It is desired, however, that only superheated water be delivered to the infusion pot and recirculation device and therefore a small vent 885 is placed I near the top of the tube 880. The result is that any preliminary vapor pressure established in the chamber 312 will be relieved by the escape of vapor through the vent 885 and warm water will not be forced over into tube 818. Now, however, when the water actually begins to boil the generation of steam pressure so far exceeds the ability of the vent 885 to allow it to escape, that pressure is built up within the chamber and water is forced up tube 380 and into tube 318. The addition of heat is continued and the water immediately superheats to an equilibrium temperature and pressure (for example approximately 227 F. at about five pounds per square inch), and the superheated water escapes rapidly at this pressure. As the water level diminishes the side walls of the container 312 become hotterand at or before the depletion of the water in the superheated water chamber 372 the bimetal 508 will have responded to the temperature rise sufliciently to break the contact 494, 504. Thereafter, if a user neglects to shut off the supply of electrical current, no damage will be done to the infusion apparatus because the bimetal will deenergize and reenergize the heating element within a definite and safe temperature range.

The superheated water entering tube 818 passes down to the condenser 378 where it is forced back up through the openings M6 in the baifie plate '4 and out of the nozzle opening 426. As soon as the infusion liquid level in the infusion pot 368 covers the openings 426 in the lower end 424 of the tube 422 such infusion liquid will enter the together with the recirculated infusion liquid runs through the openings in the cover plate M2 and drops on cOflee placed in the coffee container 4% which it extracts and drips back to the infusion pot. The purpose of the condenser is to transfer all or a part of the superheat to the infusion liquid already in the potso as to maintain the liquid at boiling during the infusion process. I

When the water is substantially exhausted from the compartment 312 and the heating element has accordingly been deenergized, the making of the infusion is complete. The infusion may be left in the compartment 368 and the remainder of the apparatus maybe lifted up and placed on another infusion-receiving compartment for making a second batch of coffee.

Various modifications of the process and appawithin the scope latching means into position to hold the infusion pot, a timing mechanism, means operable to initiate operation of the timing mechanism upon the opening of the valve and means actuated by the timing mechanism for closing said valve after a predetermined time. i

2. An apparatus for making coffee infusions comprising a support, a coffee holder mounted on said support, an infusion pot secured to said support by manually operable latching means, a source of superheated water, a passageway for conducting the superheated water into heat transferring relationship with the infusion liquid in the infusion pot and a valve in said passageway operable to open and closed position respectively by the upward or downward movement of a vertically movable valve rod, links connecting I said manually operable latching mechanism to a second vertically movable rod, means adapted to engage and lift the valve rod when the manually operable latching mechanism is moved to secure the infusion pot in place, means adapted to engage the valve' rod for holding it in raised position during the infusion process, and a timer mechanism for disengaging said last mentioned means at the end of the infusion process to permit the valve rod to drop to close the valve.

3. An apparatus for making coffee infusions comprising a compartment for receiving infusion liquid, a separate source of superheated water for infusion, means for transferring heat from the superheated water before infusion to the infusion liquid, said means comprising a tube leading from the source of superheated water and a heat exchanger with which said tube is connected, the heat exchanger comprising a compartment having baffles for circulating heated water therein and being disposed within the infusion receiving assures liquid, a separate sourceof superheated water for' comprising a supportinh member, a coffee holder infusion, means for transferring heat from the superheated water before infusion to the infusion liquid, said means comprising a. cylindrical com partment located in the infusion receiving compartmentand having a diameter which is substantially greater than its height, said compartment having diametrically opposed inlet andoutlet openings on its upper surface, and bafile plates within said compartment extending nearly from side to side of the compartment between the inlet and outlet openings, means connecting the inlet of the baffled compartment to the source of super-' heated water, and means including a coffee holder connecting with the outlet of the baflied compartment for infusing the heated water and delivering the same as infusion liquid to the infusion receiving compartment.

5. An apparatus for making coffee infusions comprising a, compartment for receiving infusion liquid, a separate source of superheated water, means for transferring heat from the superheated water to the infusion liquid comprising a tube ing superheated water through a, conduit to the topof the coffee grounds, permitting the heated water to pass downwardly through the coffee grounds for infusion and into an infusion-receiving compartment and pumping at least a part of the infusion through said conduit to the top of the coffee grounds with the superheated water for further infusion, said. superheated water being the only liquid supplied in the making of each batch of coffee. 2

7. An apparatus for making coflee infusions comprising a support, a coffee holder mounted on the support, a pot for receiving infusion liq uid engageable with the support in a position beneath the coffee holder and removable fromthe support independently of the cofiee holder, 8. source of superheated water for infusion outside the pot, and passageway means depending from the support for conducting water from said sourceto the lower portion of the pot and for 55 conducting water from said source to the coffee holder and injector means for injecting infusion liquid from the lower portion of the pot into the passageway means for recirculation to the coffee holder.

8. An apparatus for making coffee infusions according to claim 7 wherein the pot is suspended from the support and including means for detachably securing the pot to the support independently of the coffee holder.

9. Anapparatus for making coffee infusions according to claim 7 wherein the support is removably mounted on and supported by the pct. 10. An apparatus for making coffee infusions according to claim 7 wherein the support is removably mounted on top of the pot and the source of superheated water comprises a pressure chamber and heating means therefor mounted on'th support. I

11. An apparatus for making coffee infusions carried by said member, a source of hot water, a first tube supported by and depending front the supporting member connecting'at its upper end 5 with said hot water source, a second tube suplower ends of the first and second tubes for si- 19 multaneously delivering through the second, tube to the coffee holder water from the first tube and infusion liquid which has passed through the 15 comprising, preliminarily heating all the water to be infused under pressure to, superheated condition. delivering the water entirely under the pressure thus developed in a stream to a body of coffee for infusion and withdrawing and collecting 0 the resulting infusion liquid at a point removed from the superheating point, and heating the ter by conducting the superheated water in the course of delivery to the coffee in heat exchange relation with the collected infusion liquid.

13. A process of making a coffee infusion com-' prising preliminarily superheating water to be infused and gradually tlowing the water through a '30 body of coffee to form an infusion and until the desired amount of infusion has been obtained,

and in the course of delivery to the coffee conducting the superheated water in heat exchange relation with already infusedportions of the wab ter to reduce the temperature of the superheated water delivered to the coffee at least to the boiling point and heat already infused portions by absorption of the superheat from the water.

14. A process of making a, coffee infusion according to claim 18 wherein the'infused liquid is gradually recirculated through the coffee simultaneously with and solely by the delivery of the uninfused water to the coffee.

15. A process of making a coilee infusion comprising preliminarily heating water to superheated condition preparatory to making an infusion from the water, gradually delivering the water under its inherent pressure to a body of coffee and collecting the water as fast as converted to- 50 infusion liquid, and employing the superheated water. in the course of delivery to the coflee before infusion, as a. source of power to recirculate collected infusion liquid through the coffee for further infusion and also transferring heat from the superheated water to the collected liquid infusion to maintain said liquid at a temperature suitable for furtherinfusion.

' 16. An apparatus for makingcoii'ee infusions comprising a first compartment for receiving in- 0 fusion liquid, a coffee holder above said first compartment and delivering infusion liquid thereto, a second pressure water heating compartment normally closed to the atmosphere supplying the water for infusion liquid and holding sufllcient water for one batch of infusion liquid, means for V the water from said second compartment and the 

